1. Field of the Invention
The invention relates to a cycle having a front-wheel fork, a steering device connected to the front wheel fork, and a rear-wheel fork with a rear wheel that has a freewheeling hub.
2. Description of Related Art
Such a cycle is known from French Patent Reference FR-A1-2 728 532.The chassis is formed by a substantially horizontal square tube, on each side of which is a footrest for each foot in a longitudinally displaceable manner. Each footrest is connected by a cable to an associated cable pulley, connected to a sprocket wheel, of the drive, which also includes the freewheeling hub and a chain, which drives the hub, and a chain which travels on the sprocket wheel. The footrests are interconnected via an additional cable, which travels over a deflection pulley disposed at the front end of the square tube, and the footrests are alternately actuatable. Furthermore, a handrest with a handle is positioned in a longitudinally displaceable manner on each side of the square tube. The alternately actuatable handrests are connected to the sprocket wheel by additional cables and additional cable pulleys. The front-wheel fork is controlled by the rotatably disposed handles of the handrests via additional cable lines.
A similar cycle is also known from Japanese Patent Reference JP-A-09095282, but this cycle has no manual drive, though it has a steering rod connected to the front-wheel fork. These known cycles have a complex structure because of the many cables and cable pulleys and because of the separate chain drive. Additional cycles are generally known in many different forms. With conventional cycles, the chassis is a mainly triangular frame, on which are positioned the foot actuating means, which are in the form of foot pedals with at least one sprocket wheel which drives the rear wheel via the chain. There is no shortage of experiments to change this foot pedal drive in order to achieve a better sitting position, less wind resistance and/or better utilization of physical strength.
Thus, a muscle-operated driving device is known from German Patent Reference DE-U1-2 9622 231, for a non-steerable road and track vehicle which has a horizontally extending chassis with a front wheel and a driven rear wheel. A seat is securely disposed on the chassis, and a frame, which has footrests, is disposed on the chassis in a longitudinally displaceable manner. A power transmitting member includes a roller chain, and a resilient cable is secured at two different points of the chassis and guided, via a guide roller, which can be pulled by the user, via guide rollers of the chassis, guide rollers of the frame and via the driving wheel, so that a forward propulsion of the vehicle is produced by moving arms and legs. In such case, a seat is positioned on the chassis. The disadvantages of this design are that it has a complex structure and is hardly suitable as a cycle. A muscle-operated vehicle, in the form of a cycle, is known from European Patent Reference EP-A1-0 706 934, which includes a chassis which has footrests for both feet disposed at the front end thereof, and on which chassis is situated a seat which is displaceably mounted in the longitudinal direction.
The two ends of a driving traction means are secured on the seat, and the means is guided via counterrotating guide rollers of the seat, via guide rollers of the chassis and via a driving wheel of the rear wheel. A forward propulsion of the cycle can be produced by moving the seat on the chassis backwardly and forwardly. The disadvantages of such a cycle are that, when the cycle is driven, it is not possible for the user to rest its body, because the cycle is thereby made difficult to steer, and in the fact that a plurality of direction reversing locations for the driving traction means are used, and the means still has to be returned by resilient force. A three-wheeled vehicle is known from German Patent Reference DE-A1-3 516 322 and has a chassis in the form of a horizontally extending frame, a sliding seat and a tractive machine traveling on the longitudinal frame struts, which machine is securely connected to a driving traction means, and by means of which machine the steering of the front wheel is also possible. Fixed footrests are provided on the left and right sides of the frame. The driving traction means travels over a guide roller, which is disposed on the front portion of the frame, and via the driving wheel for the rear wheels. The three-wheel driving mechanism is not suitable for two-wheeled cycles. Also, the body of the user cannot adopt a resting position during the driving operation. Finally, a muscle-operated three-wheeled vehicle is known from German Patent Reference DE-U1-9 103 403, having a front axle, which has two front wheels and is horizontally pivotable, with footrests mounted on the axle for steering purposes. The vehicle has a chassis which has a frame member extending horizontally between the front wheels and rear wheel. A sliding seat travels along this frame member. A traction drum is mounted at the front end of the chassis and has a freewheeling hub, a return spring and a tension cable. Furthermore, the traction drum is connected to the rear-wheel drive by a chain via guide hubs. By pulling on the tension cable and/or stretching the legs with the aid of the sliding seat, a forward propulsion of the cycle can be achieved.
The unsafe position of the user on the seat is, however, disadvantageous. The arms of the user are not securely retained, and the support for the feet is very problematical because of the rotatability of the front axle.
One object of this invention is to provide a cycle of the type mentioned above but which has a simple structure and a simple, effective driving apparatus.
This object is achieved with features of this invention as described in the claims.
The forward propulsion of the cycle can be produced initially, by stretching the legs of the user, and the footrest is advanced. The cycle can best be steered during this driving phase because the body of the user adopts a restful position. During a second driving phase, the footrest is advanced further by the arms pulling on the steering means when the legs are stretched and the seat is pushed forwardly. During these two driving phases, a driving means drives the rear wheel. The driving means is easily returned by stretching the arms and bending the legs, whereby the footrest is pressed downwardly because of the weight of the legs, and the freewheeling hub of the rear wheel is operated in the freewheeling mode.
Further advantageous embodiments of this invention are described in the claims.
According to an additional embodiment of this invention, the bar has an angular or non-circular cross-section. For this reason, the non-rotatability of the footrest and seat on the bar is ensured in a simple manner.
According to an advantageous, further embodiment of this invention, the footrest and seat each have a slide which slides along the bar.
According to a further embodiment of this invention, the length of the bar corresponds to at least the sum of the leg length and the arm length of the user. Thus, the intended function of the drive is totally fulfilled.
According to an advantageous, further embodiment of this invention, the front-wheel fork, complete with front wheel, is disposed beneath the bar and secured on the bar by means of a fork holder.
According to an embodiment of this invention, the fork holder, complete with fork, extends inclinedly forwardly. Thus, the suspension of the front wheel is improved.
In an additional, advantageous embodiment of this invention, the portions of the steering fork extend substantially parallel to the front-wheel fork and to the fork holder, and are each bent outwardly and carry the handles at free ends.
According to an additional, advantageous embodiment of this invention, a driving loop, which contains the chain, is securable on the footrest, the loop extending longitudinally of the bar is guided by means of at least one guide wheel, which is attached to the front end of the bar, and with at least one guide wheel which is attached in the vicinity of the rear end of the bar.
According to an additional embodiment of this invention, the driving loop is guided via a guide roller secured on the fork holder. Thus, it is possible to avoid any possible contact between the driving loop and the front wheel.
According to an additional embodiment of this invention, a driving cable is securable on the footrest, the other end of which cable is windable onto a cable drum, which is connected to the freewheeling hub and is initially tensioned with a return spring. Thus, a chain and guide rollers are no longer necessary.
According to an advantageous, additional embodiment of this invention, the rear-wheel fork, secured at the rear end of the bar, extends inclinedly rearwardly. Thus, the suspension of the rear wheel is improved.